Endovascular repair reduces early and late morbidity compared to open surgery for abdominal aortic aneurysm

Preexisting right ventricular systolic dysfunction in high-risk patients undergoing non.emergent open abdominal surgery: A retrospective cohort study

Background:

The prognostic value of right ventricular systolic dysfunction in high-risk patients undergoing non-emergent open abdominal surgery is unknown. Here, we aim to evaluate whether presence of preexisting right ventricular systolic dysfunction in this surgical cohort is independently associated with higher incidence of postoperative major adverse cardiac events and all-cause in-hospital mortality.

Methods:

This is a single-centered retrospective study. Patients identified as American Society Anesthesiology Classification III and IV who had a preoperative echocardiogram within 1 year of undergoing non-emergent open abdominal surgery between January 2010 and May 2017 were included in the study. Incidence of postoperative major cardiac adverse events and all-cause in-hospital mortality were collected. Multivariable logistic regression was performed in a step-wise manner to identify independent association between preexisting right ventricular systolic dysfunction with outcomes of interest.

Results:

Preexisting right ventricular systolic dysfunction was not associated with postoperative major adverse cardiac events (P = 0.26). However, there was a strong association between preexisting right ventricular systolic dysfunction and all-cause in-hospital mortality (P = 0.00094). After multivariate analysis, preexisting right ventricular systolic dysfunction continued to be an independent risk factor for all-cause in-hospital mortality with an odds ratio of 18.9 (95% CI: 1.8-201.7; P = 0.015).

Conclusion:

In this retrospective study of high-risk patients undergoing non-emergent open abdominal surgery, preexisting right ventricular systolic dysfunction was found to have a strong association with all-cause in-hospital mortality.

Meta-analysis of long-term survival after elective endovascular or open repair of abdominal aortic aneurysm

BACKGROUND

Endovascular aneurysm repair (EVAR) has become the preferred strategy for elective repair of abdominal aortic aneurysm (AAA) for many patients. However, the superiority of the endovascular procedure has recently been challenged by reports of impaired long-term survival in patients who underwent EVAR. A systematic review of long-term survival following AAA repair was therefore undertaken.

METHODS

A systematic review was performed according to PRISMA guidelines. Articles reporting short- and/or long-term mortality of EVAR and open surgical repair (OSR) of AAA were identified. Pooled overall survival estimates (hazard ratios (HRs) with corresponding 95 per cent c.i. for EVAR versus OSR) were calculated using a random-effects model. Possible confounding owing to age differences between patients receiving EVAR or OSR was addressed by estimating relative survival.

RESULTS

Some 53 studies were identified. The 30-day mortality rate was lower for EVAR compared with OSR: 1·16 (95 per cent c.i. 0·92 to 1·39) versus 3·27 (2·71 to 3·83) per cent. Long-term survival rates were similar for EVAR versus OSR (HRs 1·01, 1·00 and 0·98 for 3, 5 and 10 years respectively; P = 0·721, P = 0·912 and P = 0·777). Correction of age inequality by means of relative survival analysis showed equal long-term survival: 0·94, 0·91 and 0·76 at 3, 5 and 10 years for EVAR, and 0·96, 0·91 and 0·76 respectively for OSR.

CONCLUSION

Long-term overall survival rates were similar for EVAR and OSR. Available data do not allow extension beyond the 10-year survival window or analysis of specific subgroups.

Preexisting Right Ventricular Dysfunction Is Associated With Higher Postoperative Cardiac Complications and Longer Hospital Stay in High-Risk Patients Undergoing Nonemergent Major Vascular Surgery

OBJECTIVES

To evaluate whether the presence of preexisting right ventricular (RV) dysfunction in high-risk patients undergoing nonemergent major vascular surgery is associated independently with higher incidents of postoperative cardiac complications and a longer length of hospital stay.

DESIGN

Retrospective chart review.

SETTING

Single-center university hospital setting.

PARTICIPANTS

The patient population consisted of those identified as American Society of Anesthesiologists classification III and above who had a preoperative echocardiogram within 1 year of undergoing nonemergent major vascular surgery between January 2010 and May 2017.

MEASUREMENTS AND MAIN RESULTS

After multivariate analyses, RV dysfunction (RVD) is associated independently with a higher incidence of postoperative major cardiac complications with an odds ratio = 6.3 (95% confidence interval [CI], 1.0-38.5; p = 0.046). In addition, patients with RVD had a 50% longer length of stay than those without RVD (incident rate ratio [95% CI], 1.5 [1.2-1.8]; p < 0.001).

CONCLUSION

In this retrospective study of high-risk patients undergoing major vascular surgery, RV dysfunction was associated independently with a higher incidence of postoperative major cardiovascular events and longer length of hospital stays. Based on current findings, the prognostic value of RVD extends beyond the cardiac surgical cohort. Knowledge in management of patients with RVD in the perioperative setting should be understood by all anesthesiologists. Of note, a future study with a larger sample size is needed to validate the current findings given the small sample size of this study.

Clinical and Functional Impact of Hypogastric Artery Exclusion During EVAR

PURPOSE

Hypogastric artery (HA) revascularization during endovascular aneurysm repair (EVAR) is still open to debate. Moreover, exclusion-related complication rates reported in literature are not negligible. The aim of this study is to present and analyze the outcomes in patients undergoing EVAR with exclusion of 1 or both HAs at our academic center.

METHODS

We retrospectively reviewed our results in patients submitted to EVAR and needing HA exclusion, in terms of perioperative (30-day) and follow-up rates of intestinal and spinal cord ischemia, buttock claudication, buttock skin necrosis, and sexual dysfunction.

RESULTS

From January 2008 to December 2014, a total of 527 patients underwent elective standard infrarenal EVAR; among those 104 (19.7%) had iliac involvement needing HA exclusion. In 73 patients with unilateral iliac involvement (70.1%, group UH), many single HAs were excluded. Thirty-one patients (29.9%) had bilateral iliac involvement (group BH), of which 16 (51.6%) had 1 HA excluded with revascularization of the contralateral one (group BHR); in the remaining 15 patients (48.4%) both HAs were excluded (group BHE). No 30-day or follow-up aneurysm-related mortality, intestinal, or spinal cord ischemia were recorded. At 30 days, skin necrosis was observed in 2 patients. Buttock claudication and sexual dysfunction rates were significantly greater in group BHE than in group BHR (P < .05). At a mean 18.6 months follow-up (range: 4-47), buttock claudication and sexual dysfunction rates in group BHE were persistently higher than that in groups UH and BHR (P < .05); HA coil embolization was significantly associated with buttock claudication and sexual dysfunction (P < .05).

CONCLUSIONS

Whenever anatomically feasible, at least 1 HA should be salvaged in case of bilateral involvement. In case of unilateral HA exclusion, the rate of complications is not negligible. Coil embolization is related to a higher complication rate.

Use of Proximal Aortic Cuffs as an Adjunctive Procedure during Endovascular Aortic Aneurysm Repair

The purpose of this study was to evaluate the incidence and durability of additional proximal cuffs during endovascular abdominal aortic aneurysm repair (EVAR). A retrospective review of 90 EVAR patients was conducted. Postoperative survival, proximal sealing zone–related complications, and secondary procedures were analyzed.

Additional proximal cuffs were used in 11%. Their use did not affect postoperative survival ( p = .58), type I endoleak rate (4.4%; p = .19), or the need for sealing zone–related secondary procedures (6.3%; p = .38) compared with patients without cuff placement but was related to a higher cumulative graft migration rate (2.2% overall p = .02). Two patients (2.5%; p = .79) underwent conversion to open surgery, both for proximal sealing zone–related complications.

Application of proximal cuffs appears to be an effective intraoperative adjunctive procedure to achieve a proximal seal during EVAR, with favorable midterm results. However, the risk of late endograft migrations may be elevated in this group.

Buttock Claudication After Interventional Occlusion of the Hypogastric Artery—A Mid-Term Follow-Up

Background. Interventional occlusion of the hypogastric artery (HA) can be used for endovascular aneurysm repair (EVAR) in the iliac arteries. Most frequent ischemic complication is buttock claudication (BC). Aim. To investigate the frequency and progression of BC after interventional occlusion of the HA prior to EVAR. Methods. A retrospective analysis was performed in patients with EVAR and occlusion of the HA between September 2004 and August 2010. Acute and persistent BC symptoms were assessed. Results. Fifty-four catheter occlusions of the HA were performed. In 10 cases, claudication could not be evaluated. During a mean follow-up of 17 months, 23 occlusions (52.3%) of the HA showed BC, in 52% symptoms were persistent. Of the 5 patients, 3 patients who underwent bilateral occlusion had BC and in 2 cases, persistent in the follow-up. Conclusion. Buttock claudication after occlusion of the HA prior to EVAR is a frequent complication, which often persists during follow-up. Alternatives that maintain pelvic perfusion should be considered.

Endovascular Abdominal Aortic Aneurysm Repair: A Community Hospital's Experience

Endovascular abdominal aortic aneurysm repair (EVAR) has become the first-line approach for the treatment of abdominal aortic aneurysms. Outcomes outside of tertiary care settings remain unknown. The purpose of this study is to report the midterm outcomes of EVAR in a community hospital. A retrospective review of 75 elective, consecutive EVARs performed at a single nonacademic community hospital was performed. There were no conversions to open repair during or after endovascular repair. The mean follow-up was 18 months. There were no postoperative ruptures or aneurysm-related deaths. At 24 months, freedom from aneurysm-related death was 100%, freedom from secondary interventions was 91%, and freedom from endoleak was 69%. EVAR in the community setting is a safe and durable procedure, even in a medically high-risk population. Comparable outcomes can be achieved to tertiary care centers, in carefully selected patients with favorable anatomy.

Comparison of the effects of open and endovascular aortic aneurysm repair on long-term renal function using chronic kidney disease staging based on glomerular filtration rate

OBJECTIVE

It has been suggested that endovascular aneurysm repair (EVAR) in concert with serial contrast-enhanced computed tomography (CT) surveillance adversely impacts renal function. Our primary objectives were to assess serial renal function in patients undergoing EVAR and open repair (OR) and to evaluate the relative effects of method of repair on renal function.

METHODS

A thorough retrospective chart review was performed on 223 consecutive patients (103 EVAR, 120 OR) who underwent abdominal aortic aneurysm (AAA) repair. Demographics, pertinent risk factors, CT scan number, morbidity, and mortality were recorded in a database. Baseline, 30- and 90-day, and most recent glomerular filtration rate (GFR) were calculated. Mean GFR changes and renal function decline (using Chronic Kidney Disease [CKD] staging and Kaplan-Meier plot) were determined. EVAR and OR patients were compared. CKD prevalence (>or=stage 3, National Kidney Foundation) was determined before repair and in longitudinal follow-up. Observed-expected (OE) ratios for CKD were calculated for EVAR and OR patients by comparing observed CKD prevalence with the expected, age-adjusted prevalence.

RESULTS

The only baseline difference between EVAR and OR cohorts was female gender (4% vs 12%, P = .029). Thirty-day GFR was significantly reduced in OR patients (P = .047), but it recovered and there were no differences in mean GFR at a mean follow-up of 23.2 months. However, 18% to 39% of patients in the EVAR and OR groups developed significant renal function decline over time depending on its definition. OE ratios for CKD prevalence were greater in AAA patients at baseline (OE 1.28-3.23, depending upon age group). During follow-up, the prevalence and severity of CKD increased regardless of method of repair (OE 1.8-9.0). Deterioration of renal function was independently associated with age >70 years in all patients (RR 2.92) and performance of EVAR compared with OR (RR 3.5) during long-term follow-up.

CONCLUSIONS

Compared with EVAR, OR was associated with a significant but transient fall in GFR at 30 days. Renal function decline after AAA repair was common, regardless of method, especially in patients >70 years of age. However, the renal function decline was significantly greater by Kaplan-Meier analysis in EVAR than OR patients during long-term follow-up. More aggressive strategies to monitor and preserve renal function after AAA repair are warranted.

The Durability of Evar — What are the Evidence and Implications on Follow-Up?

Background and Aims:

To investigate the durability of EVAR and to explore the evidence for follow-up investigations. Furthermore, to study the patients' impressions of follow-up investigations, and how complications and secondary procedures influence cost-effectiveness.

Material and Methods:

263 patients were treated by EVAR from february 1995-february 2007. The series is divided into two groups with the year 2000 as a cut-off point since a new generation of stent grafts was then introduced. Early and late complications and secondary procedures were recorded. A questionnaire study was performed to investigate the patients' views on the follow-up program.

Results:

There was a significant reduction of complications from period I to period II, which was also reflected in the reduction of secondary procedures. Freedom from secondary procedures were 47% and 93% at 5 years follow-up in the two periods, respectively. In phase II, 7.5% of the patients needed a secondary procedure. Limb extension and femoro-femoral bypass were the most common procedures. Since late complications still occur, and can be unpredictable, a follow-up program is necessary. The vast majority of the patients tolerated the follow-up program well.

Conclusions:

Although the number of complications following EVAR has decreased significantly over the years, a thorough follow-up program is still necessary. This follow-up regime is well tolerated by the patients. Reduction of secondary procedures is important to improve the cost-effectiveness of EVAR.

Long-term durability of open abdominal aortic aneurysm repair

OBJECTIVE

In multiple comparisons of open vs endovascular (EVAR) repair of abdominal aortic aneurysms, the prior assumption that open repair produced superior durability has been challenged by advocates of EVAR. Although focus on EVAR reintervention has been intense, few contemporary studies document late outcomes after open repair; this was the goal of this study.

METHODS

From January 1994 to December 1998 (chosen to ensure a minimum 5-year follow-up), 540 patients underwent elective open repair. Surveillance imaging (computed tomographic and magnetic resonance imaging scans) was obtained for 152 (57%) of the 269 patients who remained alive at a mean follow-up of 87 months. Study end points included freedom from graft-related interventions and aneurysm-related and overall survival (Kaplan-Meier test); factors predictive of these end points were determined by multivariate analysis.

RESULTS

The mean age at operation was 73 years. A total of 76% of patients were male; 11% had renal insufficiency (creatinine > or =1.5 mg/dL), and 13% had chronic obstructive pulmonary disease. The aortic cross-clamp position was suprarenal in 135 (25%) patients, and 284 (53%) of patients had bifurcated grafts placed. Operative mortality (30 days) was 3%, and the median length of hospital stay was 7 days. Postoperative complications occurred in 68 (13%) patients. Predictors of postoperative complications included a history of myocardial infarction (hazard ratio [HR], 2.0; P = .01) and renal insufficiency (HR, 2.5; P = .02). The mean follow-up for all patients was 87 months. Actuarial survival was 70.7% +/- 2% and 44.3% +/- 2.4% at 5 and 10 years, respectively. Negative predictors of long-term survival included advanced age (HR, 1.1; P < .001), history of myocardial infarction (HR, 1.37; P = .02), and renal insufficiency (HR, 1.5; P = .04). Freedom from graft-related reintervention was 98.2% +/- 0.8% and 94.3% +/- 3.4% at 5 and 10 years, respectively. There were 13 late graft-related complications in 11 (2%) patients (mean follow-up, 7.2 years). Findings included seven anastomotic pseudoaneurysms (five were repaired), four graft limb occlusions, and two graft infections. Aneurysms were identified in noncontiguous arterial segments in 68 (45%) of 152 patients, most of which involved the iliac arteries and required no treatment because of small size. Late aortic aneurysms proximal to the repair were identified in 24% of patients, and 29 (19%) patients had multiple late synchronous aneurysms.

CONCLUSIONS

Open repair remains a safe and durable option for the management of abdominal aortic aneurysms, with an excellent associated 10-year survival in patients who undergo operation at 75 years of age or younger. In addition, the freedom from graft-related reintervention is superior to that of EVAR. Finally, continued surveillance after open repair is appropriate and should be directed toward the detection of other aneurysms.

Propensity score analysis in observational studies: outcomes after abdominal aortic aneurysm repair

OBJECTIVE

Large databases composed of well-designed prospectively collected cohort data provide an opportunity to examine and compare healthcare treatments in actual clinical practice settings. Because the analysis of these data often leads to a retrospective cohort design, it is essential to adequately adjust for lack of balance in patient characteristics when making treatment comparisons. We used matched propensity scoring in a cohort of patients undergoing elective aneurysm repair as an illustrative example of this important statistical method that adjusts for baseline characteristics and selection bias by matching covariables.

METHODS

By using prospectively collected clinical data from the National Surgical Quality Improvement Program of the Department of Veterans Affairs, we studied 30-day mortality, 1-year survival, and postoperative complications in 1904 patients who underwent elective AAA repair (endovascular aneurysm repair [EVAR], n=717 (37.7%); open aneurysm repair, n=1187 [62.3%]) at 123 Veterans Health Administration's hospitals between May 1, 2001, and September 30, 2003. In bivariate analysis, patient characteristics and operative and hospital variables were associated with both type of surgery and outcomes of surgery. Therefore, the predicted probability of receiving EVAR was tabulated for all patients by using multiple logistic regression to control for 32 independent demographic and clinical characteristics and then stratified into 5 groups. Patients were matched within strata based on similar levels of the independent measures (a propensity score technique), creating a pseudo-randomized control design. The proportion of patients with the morbidity and mortality outcomes was then compared between the EVAR and open procedures within strata to control for selection.

RESULTS

Patients undergoing EVAR had significantly lower unadjusted 30-day (3.1% versus 5.6%, P=.01) and 1-year mortality (8.7% versus 12.1%, P=.018) than patients undergoing open repair. By using propensity scoring, the proportions of EVAR patients experiencing 30-day mortality were equal or less than patients undergoing open procedures for all levels of probability and decreased as the probability of EVAR increased. Furthermore, propensity scoring also showed that patients having EVAR had lower 1-year mortality and experienced fewer perioperative complications.

CONCLUSIONS

We used a propensity score approach to examine outcomes after elective AAA repair to statistically control for many factors affecting both treatment selection and outcome. Patients who underwent elective EVAR had substantially lower perioperative mortality and morbidity rates compared with patients having open repair, which was not explained solely by patient selection in an observational dataset.

Secondary conversion of the Gore Excluder to operative abdominal aortic aneurysm repair

OBJECTIVE

Reports continue to document the occurrence of major adverse events after endovascular aortic aneurysm repair. Although many of these problems can be successfully managed through endovascular salvage, operative conversion with explantation of the endoprosthesis remains necessary in some patients. We report herein a review of all patients initially enrolled in multicenter US clinical trials of the Excluder endograft who underwent secondary conversion to open surgical repair.

METHODS

Clinical data and relevant medical records of patients enrolled in phase I and II multicenter US clinical trials of the Excluder endograft were retrospectively reviewed for adverse events and further narrowed to those patients who underwent secondary operative conversion. Hospital records, operative and anesthesia reports, and all imaging studies were analyzed at initial implantation and at the time of subsequent open surgical repair.

RESULTS

Late open conversion was performed in 16 (2.7%) of the 594 patients enrolled in the Excluder clinical trials. Presumed endotension accounted for 8 of 16 of secondary conversions. In two of these patients, however, an endoleak was identified at the time of open surgical repair. Of the remaining eight patients, two underwent conversion for device infection, five for persistent endoleak, and one for aneurysm rupture. The overall 30-day mortality was 6.25% (1/16), with one death occurring in a patient with a ruptured aneurysm. Of patients who underwent conversion because of endotension, the maximal abdominal aortic aneurysm diameter (mean +/- SD) at the time of initial implantation and subsequent graft removal was 61 +/- 11 mm and 70 +/- 10 mm, respectively. The mean time to open conversion for treatment of endotension was 37 +/- 12 months (range, 20-50 months; median, 42 months). Freedom from conversion was 98.6% and 96.7% at 24 and 48 months, respectively.

CONCLUSIONS

Endotension in the absence of a demonstrable endoleak has been a major indication for late surgical conversion in patients treated with the Excluder endograft. Given the potential presence of an undetected endoleak and the possible effects of progressive sac enlargement on long-term device stability, continued close surveillance of patients with assumed endotension is required. Should changes in device design eliminate endotension, a further reduction in the already low incidence of late open conversion of the Excluder endograft can be anticipated.

Systematic review of recent evidence for the safety and efficacy of elective endovascular repair in the management of infrarenal abdominal aortic aneurysm

Background

Conventional management of abdominal aortic aneurysm (AAA) is by open repair and is associated with a mortality rate of 2–6 per cent. Endovascular aneurysm repair (EVAR) is an alternative technique first introduced in 1991. A systematic review was undertaken of the evidence for the safety and efficacy of elective EVAR in the management of asymptomatic infrarenal AAA.

Methods

Thirteen electronic bibliographical databases were searched, covering biomedical, health-related, science and social science literature. Outcomes were assessed with respect to efficacy (successful deployment, technical success, conversion rates and secondary intervention rates) and safety (30-day mortality rate, procedure morbidity rates and technical issues—endoleaks, graft thrombosis, stenosis and migration).

Results

Of 606 reports identified, 61 met the inclusion criteria (three randomized and 15 non-randomized controlled trials, and 43 uncontrolled studies). There were 29 059 participants in total; 19 804 underwent EVAR. Deployment was successful in 97·6 per cent of cases. Technical success (complete aneurysm exclusion) was 81·9 per cent at discharge and 88·8 per cent at 30 days. Secondary intervention to treat endoleak or maintain graft patency was required in 16·2 per cent of patients. Mean stay in the intensive care unit and mean hospital stay were significantly shorter following EVAR. The 30-day mortality rate for EVAR was 1·6 per cent (randomized controlled trials) and 2·0 per cent in nonrandomized trials and case series. Technical complications comprised stent migration (4·0 per cent), graft limb thrombosis (3·9 per cent), endoleak (type I, 6·8 per cent; type II, 10·3 per cent; type III, 4·2 per cent) and access artery injury (4·8 per cent).

Discussion

EVAR is technically effective and safe, with lower short-term morbidity and mortality rates than open surgery. However, there is a need for extended follow-up as the long-term success of EVAR in preventing aneurysm-related deaths is not yet known.

Combining open and endovascular surgery for the treatment of infrarenal abdominal aortic aneurysm: A case report using a hybrid vascular graft

Migration and endoleaks after endovascular exclusion of an infrarenal abdominal aortic aneurysm may lead to long-term failure of the stent graft. We report a successful case of a novel technique that combined open and endovascular surgery to address the issues of migration and endoleak in the repair of an abdominal aortic aneurysm. The hybrid graft, consisting of a proximal, conventional Dacron graft and two distal endoprosthesis limbs, was designed to reduce aortic cross-clamp time in aortic procedures. This is the first reported clinical experience with this new hybrid vascular graft for the treatment of an abdominal aortic aneurysm.

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.

Six-Year Experience With Talent Stent-Graft Repair of Abdominal Aortic Aneurysms

PURPOSE

To report a long-term experience with the Talent Endoprosthesis for the treatment of abdominal aortic aneurysm (AAA).

METHODS

In the period between June 1997 and June 2003, 193 patients (171 men; mean age 71.0+/-7.8 years, range 52-89) with AAA were treated with a Talent Endoprosthesis. Patients were clinically and radiologically followed in the postoperative period, at 30 days, and then annually up to 72 months. In addition to computed tomographic scans, a plain abdominal radiogram was also performed annually for structural assessment of the stent-graft.

RESULTS

Implantation success was 99.0% (191/193). Delivery system introduction was the cause of 1 failure, and the other patient was converted to surgery for intraprocedural device migration. There were 10 (5.2%) endoleaks (3 type I, 7 type II) at 30 days; all type I and 3/7 type II endoleaks were treated (93.3% secondary clinical success). Seven (3.7%) patients died in the perioperative period, including the conversion. During follow-up, 18 (9.3%) additional deaths occurred, and 4 new endoleaks (1 type I, 2 type II, 1 type III) were encountered. In up to 6 years' follow-up, the Talent Endoprosthesis did not present signs of material fatigue, but 1 component disconnection at 42 months led to death. There was no aneurysm rupture. After an initial increase in the aortic neck (1.2+/-1.1 mm) in the postoperative period, the neck diameters continued to increase until after the third year. An average reduction of 5.6+/-4.1 mm in the aneurysm diameter at 1 year was noted; the reduction gradually reached 14.1+/-10.7 mm after 60 months.

CONCLUSIONS

The Talent Endoprosthesis was an efficient alternative for managing AAAs, achieving low morbidity and mortality rates and a good long-term clinical outcome in this study. The Talent Endoprosthesis did not present signs of material fatigue over a 6-year follow-up.

Endovascular Treatment of an AcutelyThrombosed AAA

PURPOSE

To report a case of lower extremity ischemia due to acute thrombosis of an abdominal aortic aneurysm (AAA) that was successfully treated with emergent stent-graft placement.

CASE REPORT

A 58-year-old hypertensive man was transferred from an outside hospital with the history of sudden onset of pain, paresis, and purple discoloration of both lower extremities extending up to the umbilicus. Femoral and distal pulses were absent on examination. Contrast-enhanced computed tomography showed a 3.8-cm infrarenal AAA with a large thrombus occluding the bifurcation of the iliac arteries. The patient was treated emergently with an AneuRx stent-graft that excluded the thrombus and the AAA from the circulation, with return of distal pulsation and recovery of ischemic and neurological deficits. At 10-month follow-up, the patient remained asymptomatic.

CONCLUSIONS

Selected cases of acute thrombosis of AAA with favorable anatomy can be treated utilizing endovascular grafts. Extra precaution should be taken to prevent embolization during catheter manipulation and introduction of the large stent-graft devices.

Hospital Readmissions Following Abdominal Aortic Aneurysm Repair

In-hospital outcomes associated with abdominal aortic aneurysm (AAA) repair are well described. However, little is known about post-discharge readmission rates, lengths of stay, associated mortality, and costs. We examined 206 consecutive patients who underwent AAA repair at two American hospitals between 1998 and 2000. Index hospitalization and 6-month readmission data were extracted from a resource and cost accounting system used by both hospitals. Among the 206 patients, 183 survived until discharge (mortality rate 11.2%). Among the surviving patients, 38 (21.0%) were readmitted within 6 months. Half of the readmissions occurred within two weeks of discharge, with patients presenting with a diverse array of complications. Nonelective repair and diabetes mellitus were independent predictors of hospital readmission (OR = 2.83, 95% CI = 1.25-6.40, p = 0.01; OR = 6.60, 95% CI = 1.02-42.4, p = 0.047, respectively). For each readmission, the mean length of stay was 10.7 +/- 2.5 days and the mean cost was dollar 13,397 +/- 3,381. The cumulative number of hospital days during the 6 months post-discharge was 17.7 +/- 3.5 days for each readmitted patient and the mean per-patient total cost was dollar 23,262 +/- 5,478. The mortality rate among readmitted patients was 13.2%. Overall, readmissions following AAA repair accounted for a cost >50% over and above the cost of the readmitted patients' index hospitalization. Hospital readmissions are common during the 6 months following AAA repair. Patients who are readmitted experience long lengths of stay and high mortality rates, and their care incurs high costs.

Type II endoleak in porcine model of abdominal aortic aneurysm

PURPOSE

The purpose of this study was to develop a reliable in vivo porcine model of type II endoleak resulting from endovascular aortic aneurysm repair (EVAR), for the study and treatment of type II endoleak.

METHODS

Eight pigs underwent creation of an infrarenal aortic aneurysm, with a Dacron patch with preservation of lumbar branches. An indwelling pressure transducer was placed in the aneurysm sac. After 1 week the animals underwent EVAR with a custom-made Talent endograft. After another week the animals underwent laparoscopic lumbar artery ligation. Abdominal and pelvic computed tomography was performed after each procedure. Aneurysm sac pressure was measured in sedated and awake animals.

RESULTS

All eight animals underwent successful creation of an aortic aneurysm and EVAR resulting in exclusion of the aneurysm sac. After creation of the aneurysm the sac mean arterial pressure (MAP) was 72.5 +/- 6.1 mm Hg and the sac pulse pressure was 44.8 +/- 8.7 mm Hg. Postoperative computed tomography scans demonstrated a type II endoleak from the lumbar branches in all animals. While aneurysm sac MAP (56.5 +/- 7.9 mm Hg; P <.01) and pulse pressure (13.6 +/- 4.1 mm Hg; P <.01) decreased after EVAR, sac pulse pressure remained, with type II endoleak. All animals underwent laparoscopic lumbar artery ligation, which resulted in further reduction in the sac MAP (38.3 +/- 4.6 mm Hg; P <.02) and immediate absence of sac pulse pressure (0 mm Hg; P <.01). Necropsy confirmed the absence of collateral flow in the aneurysm sac, with fresh thrombus formation in all animals.

CONCLUSION

We present a reliable and clinically relevant in vivo large animal model of type II endoleak.

CLINICAL RELEVANCE

We set out to show that aortic aneurysm sac pressurization caused by lumbar arterial flow in the setting of type II endoleak can be reproduced in an in vivo porcine model of endovascular aortic aneurysm repair. Indeed, in this model the aneurysm sac pulse pressure was a sensitive indicator of type II endoleak, correlating well with findings at computed tomography, and lumbar artery ligation eliminated the endoleak, as demonstrated on computed tomography scans and sac pressure measurement. Therefore we believe this in vivo large animal model can be instrumental in the study of many aspects of the physiologic features of type II endoleak.

Quality of life before and after endovascular and retroperitoneal abdominal aortic aneurysm repair

PURPOSE

This study was undertaken to evaluate changes in quality of life and to compare conventional outcomes in patients undergoing endovascular and open retroperitoneal abdominal aortic aneurysm (AAA) repair.

METHODS

Between October 2000 and May 2003, 129 patients underwent elective AAA repair, endovascular repair in 22 patients and open retroperitoneal repair in 107 patients. The Short-Form Health Survey, 12 items (SF-12) was administered preoperatively and at 3 weeks, 4 months, and 1 year after discharge. Quality of life, hospital and intensive care unit stay, perioperative complications, discharge disposition, readmission, and hospital cost were statistically evaluated.

RESULTS

For the total group, significant differences were observed for both Physical Component Summary scores (P<.001) and Mental Component Summary scores (P=.001) between time points. There were no significant differences for either Component Summary score between open and endovascular procedures for any time period. Number of weeks required to return to baseline functional status was similar after either open or endovascular repair (7.22 vs 5.47 weeks, respectively; P=.09). Mean hospital and intensive care unit stay was 4.4 and 1 days, respectively, for open repair versus 1.9 and 0 days, respectively, for endovascular repair (P<.0001). No significant difference between groups was observed in terms of perioperative complications, discharge disposition, or hospital readmission (P> or =.54). Mean total hospital cost for endovascular repair was 1.60 times that for open repair (mean difference, $11,662; P<.0001; 95% confidence interval, $17,799-$5525).

CONCLUSIONS

Hospital stay is significantly shorter after endovascular AAA repair. However, hospital cost is almost twice that for open retroperitoneal repair. Perioperative complications, discharge disposition, and hospital readmission are not statistically different between the two groups. Effect on health-related quality of life is similar after either open retroperitoneal or endovascular AAA repair.

Management of Aneurysm Sac Hygroma

PURPOSE

To document the management strategies and outcome of patients diagnosed with sac hygroma following open or endovascular abdominal aortic aneurysm (AAA) repair.

METHODS

Seven men (median 68 years, range 43-79) with previous open (n=3) or endovascular (n=4) AAA repairs and increasing aneurysm diameters documented on spiral computed tomography (CT) were diagnosed with sac hygroma based on the lack of a demonstrable endoleak on CT imaging; the presence of a gelatinous, clear fluid in the sac; and a nonpulsatile sac pressure that was about one third of the systemic blood pressure. The patients were followed at regular intervals with spiral CT and percutaneous CT-guided translumbar intrasac pressure measurements. Surgical interventions were performed for sac diameter increase >5 mm or expansion-related pain. Blood samples and fluid aspirated from the sac were analyzed to detect activation of the coagulation and fibrinolytic systems.

RESULTS

Over a median 21.5-month follow-up, open fenestration with resection of the aneurysm wall or open tight wrapping of the wall around the graft in 4 patients did not prevent hygroma reoccurrence, nor did repeated punctures with aspiration of fluid in the other 3 patients. Aneurysm diameters remained unchanged during the observation period.

CONCLUSIONS

Only symptomatic hygromas need be treated, but the treatment of choice remains to be established, since puncture, fenestration, or resection of the sac do not seem to be adequate.

Rupture of Infra-renal Aortic Aneurysm after Endovascular Repair: A Series from EUROSTAR Registry

OBJECTIVES

Although small, the risk of rupture after EVAR remains a major concern. The aim of this study was to identify mechanisms of late aneurysm rupture after endovascular repair.

METHODS

Patients who suffered a proven aneurysm rupture after EVAR were identified from the EUROSTAR (European Collaborators on Stent-graft Techniques for Abdominal Aortic Aneurysm Repair) registry. Complications preceding rupture were studied to identify common patterns and possible mechanisms of late rupture.

RESULTS

A rupture was documented in 34 patients resulting in death of 21 (62%). Adverse events documented during previous follow-up in these patients included endoleak (30%), migration (18%), limb occlusion (12%) and kinking (12%). The findings at time of rupture were documented in 24 patients and including endoleak: Type III (10), Type I (9), Type II (1); stent-graft disintegration (2) and migration (3). Aneurysm diameter changes could be ascertained in 24 patients and had increased in only seven.

CONCLUSION

The importance of graft-related endoleak, stent-graft disintegration and migration in the causation of aneurysm rupture was confirmed. Poor compliance with follow-up schedule was also identified as a common feature. However, the absence of complications in some patients, who attended regularly for follow-up, highlights the difficulty of predicting rupture after EVAR.