Aneurysm regression after endovascular aneurysm repair: what should we expect?

This study reviewed a large national core laboratory database for the Ancure (Guidant, Menlo Park, California) phase I and II trial of overall aneurysm sac regression after endovascular aneurysm repair. Data were reviewed for aneurysm size and endoleak in follow-up. Endoleak was recorded as well as maximum major and minor axis aortic diameters. Included were patients with baseline assessment within 3 months of implantation and at least 24 months of follow-up, and 444 were available for review. The mean baseline aortic diameter was 56.6 mm; mean follow-up was 48.7 months. Of these patients, 129 (29.5%) had aneurysm regression to less than 40 mm, 42 (9.5%) regressed to less than 35 mm, and 12 (2.7%) had complete aneurysm sac obliteration. Multivariate analysis demonstrated that baseline aneurysm size was the only predictor of aneurysm size regression. Significant sac regression is common after Ancure aneurysm repair and appears to be related primarily to initial aneurysm size.     

Are type II endoleaks after endovascular aneurysm repair endograft dependent?

PURPOSE: Most clinical end points after endovascular aneurysm repair (EVAR) are endograft-specific, but type II endoleaks have been assumed to be an unavoidable consequence of the repair method and independent of the type of endograft used. Some recent data have suggested that the rate of type II endoleaks may also be graft-dependent. We reviewed a large clinical experience with six endografts to determine the behavior of type II endoleaks and whether they are graft-specific. METHODS: All elective EVAR cases from five university institutions from 1996 to 2003 were retrospectively analyzed. Endografts used in <50 patients were excluded. Endoleaks were diagnosed and classified from contrast-enhanced computed tomography (CT) scans by the treating surgeons. Results of angiography and interventions for endoleaks were tracked. The rate of type II endoleaks was compared among endografts at 1, 6, and 12 months, and yearly thereafter. Statistical significance was defined as P < .05. RESULTS: During the study period, 1909 patients underwent elective EVAR and had an adequate imaging follow-up at one of the specified time points. At 1 month, the overall rate of type II endoleak was 14.0% (range, 9.8% to 25.2%.) The Excluder had a significantly higher incidence of type II endoleaks at 1 month but was similar to most other grafts during longer follow-up. At 6 months, the overall rate of type II endoleak was 16.3% (range, 8.3% to 16.8%). The Talent and Lifepath had an apparent lower initial rate of type II leaks, but this was only significant for the Talent at 6 months compared with Excluder, Zenith, and Ancure, and at 1 year compared with Excluder and Zenith. No graft had a long-term statistically significant difference in the rate of type II endoleak formation. Intervention rates varied by institution and graft type but in general were quite low. Of 25 successful interventions (Ancure, 12; AneuRx, 8; Excluder, 2; Lifepath, 2; Zenith, 1; Talent, 0), 21 were performed during the first year. Interim spontaneous resolution, defined as a negative CT scan after a CT positive for endoleak, was high, especially in the first year. Resolution of type II endoleaks occurred in 54 (33%) of 164 between 1 and 6 months, in 37 (33%) of 112 between 6 and 12 months, in 20 (35%) of 57 from 12 to 24 months, and in 5 (20%) of 25 between 24 and 36 months. The various grafts had a nearly identical pattern, but the rates were highest for the Talent. Late appearing endoleaks, defined as a positive CT after a negative CT, were frequent. At 6 months, 44 (30%) of 147 type II endoleaks were newly diagnosed. The rates were 37 (35%) of 107 at 12 months, 15 (27%) of 56 at 2 years and 5 (25%) of 20 at 3 years. No conversions to open repair for type II endoleaks were noted in the first 4 years. The thrombus burden could not be determined in this analysis. CONCLUSIONS: Type II endoleaks occur in nearly 15% of patients treated by EVAR. The early incidence varies only slightly with graft type. The long-term prevalence and clinical significance are masked by different treatment patterns, spontaneous resolution, newly evident endoleaks, and aneurysm size at initial treatment.     

Will endovascular repair replace open surgery for abdominal aortic aneurysm repair?

OBJECTIVE: To evaluate of the impact of endovascular aneurysm repair on the rate of open surgical repair and on the overall treatment of abdominal aortic aneurysms (AAAs). METHODS: All patients with AAA who were treated during two consecutive 40-month periods were reviewed. During the first period, only open surgical repair was performed; during the subsequent 40 months, endovascular repair and open surgical repair were treatment options. RESULTS: A total of 727 patients with AAA were treated during the entire period. During the initial 40 months, 268 patients were treated with open surgical repair, including 216 infrarenal (81%), 43 complex (16%), and 9 ruptured (3%) aortic aneurysms. During the subsequent 40 months, 459 patients with AAA were treated (71% increase). There was no significant change in the number of patients undergoing open surgical repair and no significant difference in the rate of infrarenal (238 [77%]) and complex (51 [16%]) repairs. A total of 353 patients were referred for endovascular repair. Of these, 190 (54%) were considered candidates for endovascular repair based on computed tomography or arteriographic morphologic criteria. Analyzing a subgroup of 123 patients, the most common primary reasons for ineligibility for endovascular repair were related to morphology of the neck in 80 patients (65%) and of the iliac arteries in 35 patients (28%). A total of 149 patients underwent endovascular repair. Of these, the procedure was successful in 147 (99%), and 2 (1%) patients underwent surgical conversion. The hospital death rate was 0%, and the 30-day death rate was 1%. During a follow-up period of 1 to 39 months (mean 12 +/- 9), 21 secondary procedures to treat endoleak (20) or to maintain graft limb patency (1) were performed in 17 patients (11%). There were no aneurysm ruptures or aneurysm-related deaths. CONCLUSIONS: Endovascular repair appears to have augmented treatment options rather than replaced open surgical repair for patients with AAA. Patients who previously were not candidates for repair because of medical comorbidity may now be safely treated with endovascular repair.     

Effect of β-blocker on aneurysm sac behavior after endovascular abdominal aortic repair

Objective

This study was conducted to determine whether β-blocker (BB) therapy is associated with abdominal aortic aneurysm (AAA) sac regression after endovascular abdominal aortic repair (EVAR).

Endoleaks during follow-up after endovascular repair of abdominal aortic aneurysm. Are they all dangerous?

AIM: Development of endovascular abdominal aortic aneurysm repair (EVAR) has been accompanied by previously unencoutered complications. The most challenging but least understood of these complications is incomplete seal of the endovascular graft (endoleak), a phenomenon which has a variety of causes. An important consequence of endoleakage may be persistent pressurisation of the aneurysm sac, which may ultimately lead to post-EVAR rupture. METHODS: Data of 110 European centers were recorded in a central database (EUROSTAR). Patient, anatomic characteristics and operative and device details were correlated with the occurrence of different types of endoleaks. Outcome events during follow-up, notably expansion of the aneurysm, incidence of conversion to open repair and post-EVAR rupture were assessed in the different categories of endoleaks and in a group of patients without any endoleak. RESULTS: Type I and III endoleak were associated with an increased frequency of open conversions or risk of rupture of the aneurysm. Device-related endoleaks also correlated with an increased need for secondary interventions. These types of endoleak need to be treated without delay, and when no other possibilities are present, an open conversion to avert the risk of rupture should be considered. Endoleaks type II do not pose an indication for urgent treatment. However, they may not be harmless, as there was a frequent association with enlargement of aneurysm and reinterventions. CONCLUSION: Our findings suggest that more frequent surveillance examinations are indicated than in patients without collateral endoleak. The indication for intervention is primarily dictated by documented expansion of the aneurysm.     

Is elevated creatinine level a contraindication to endovascular aneurysm repair?

PURPOSE: It is widely believed that chronic renal insufficiency (CRI) greatly increases the risk associated with endovascular abdominal aortic aneurysm repair (EVAR) and is a relative contraindication to the procedure and to the use of intra-arterial contrast agents (IACA). We reviewed a 5-year EVAR experience to determine whether the procedure and use of IACA have an important deleterious effect on renal function in patients with and without pre-existing CRI. METHODS: Endovascular aneurysm repair (EVAR) was performed in 200 patients with a variety of endografts, with intra-arterial contrast agents. The patients were retrospectively assigned to three groups on the basis of preoperative serum creatinine concentration (Cr): group 1 (n = 108), Cr less than 1.5 mg/dL (normal range); group 2 (n = 65), Cr 1.5 to 2.0 mg/dL; group 3 (n = 27), Cr 2.1 to 3.5 mg/dL. No patients had undergone hemodialysis. In groups 2 and 3, patients received hydration perioperatively, and received mannitol intraoperatively; no nephrotoxic drugs were administered during the procedure, other than nonionic contrast agent (Omnipaque 350). RESULTS: The incidence of postoperative complications between the three study groups was not statistically different. In group 1 a transient increase in serum Cr (>30% over baseline and >1.4 mg/dL) was noted in three patients (2.7%), two of whom (1.9%) required temporary hemodialysis and one (0.9%) who died of renal failure. In group 2 a transient increase in serum Cr was noted in two patients (3.1%); both patients (3.1%) required temporary hemodialysis, and one patient (1.5%) died of renal failure. In group 3 a transient increase in serum Cr was noted in two patients (7.4%); one patient (3.7%) required temporary hemodialysis, and one patient (3.7%) died of renal failure. Perioperative hypotension significantly increased the risk for elevated serum Cr and death (P <.05), and larger contrast volume was associated with an increase in serum Cr (P <.05) during the postoperative period. CONCLUSIONS: EVAR with intra-arterial contrast agents can be accomplished in patients with chronic renal insufficiency who do not require dialysis, with limited and acceptable morbidity and mortality, similar to that observed with open aneurysm repair. Contrary to other reports in which perioperative precautions were not used, our study shows that with EVAR the risk for worsening renal failure, dialysis, and death is only slightly, and not significantly, greater in patients with preoperative chronic renal insufficiency compared with patients with normal renal function. Perioperative hypotension and increased contrast volume are significant risk factors for postoperative increase in serum Cr and death. With appropriate precautions such as averting perioperative hypotension and limiting the volume of nonionic contrast agents, elevated Cr need not be a contraindication to EVAR with intra-arterial contrast agents.     

Does endovascular aortic aneurysm repair justify a reduced cardiology work-up?

Endovascular repair of abdominal aortic aneurysms (EVAR) has been introduced as an alternative to open surgery with the purpose of reducing operative risk and improving survival. Since cardiac co-morbidity is a major risk factor for both the operative procedure and long-term survival, it seems worthwhile to compare the cardiac implication of the 2 procedures. If EVAR would indeed afford a cardioprotective effect, this could have clinical consequences. Preoperative cardiology work-up could be reduced and more high-risk patients could be treated. A review of the literature has been made focusing on studies that examined cardiology work-up and cardiac risk profile of EVAR and open surgery. Most literature data suggest that cardiac risk is indeed reduced with EVAR, since hemodynamic alterations are less severe, episodes of anaemia are less frequent, plasma catecholamine levels are lower and general anaesthesia can be avoided. There is no level I or II evidence that immediate or late cardiac complications are indeed reduced with EVAR. At present, there are not enough literature data on the cardiac implications of EVAR to justify a reduced preoperative cardiology work-up. Even if conclusive evidence was available that EVAR reduces operative cardiac risk, the value of preoperative cardiac screening and myocardial revascularisation would remain unchanged: the purpose of cardiology work-up is not only to reduce operative risk but also to improve long-term survival.     

Does hostile neck anatomy preclude successful endovascular aortic aneurysm repair?

OBJECTIVES: Poor outcomes have been reported with endovascular aneurysm repair (EVAR) in patients with hostile neck anatomy. Unsupported endografts with active fixation may offer certain advantages in this situation. We compared EVAR results using the Ancure (Guidant) endograft in patients with and without hostile neck anatomy. METHODS: Records of EVAR patients from October 1999 to July 2002 at a tertiary care hospital were retrospectively reviewed from a division database. Patients with elective open abdominal aortic aneurysm (AAA) repair during the same period were reviewed to determine those unsuitable for EVAR. Hostile neck anatomy, assessed by computer tomography (CT) scans and angiograms, was defined as one or more of the following: (1) neck length 3 mm, (3) >2-mm reverse taper within 1 cm below the renal arteries, (4) neck thrombus > or =50% of circumference, and (5) angulation > or =60 degrees within 3 cm below renals. RESULTS: Three hundred and twenty-two patients underwent EVAR with an average follow-up of 18 months. Patients in Phase II trials (n = 41), repaired with other graft types (n = 48), or without complete anatomic records (n = 27) were excluded. Demographics and co-morbidities were similar in the 115 good-neck (GN) and 91 bad-neck (BN) patients except for age (mean, 72.9 years GN vs 75.7 BN; P = 0.13), gender (11% female GN vs 22% BN; P =.04); neck length (mean, 21.8 mm GN vs 14.4 mm BN: P <.001), and angulation (mean, 22 degrees GN vs 40 degrees BN; (P <.001). Perioperative mortality (0 GN vs 1.1% BN), late mortality (5.2% GN vs 4.4% BN), all endoleaks (19.1% GN vs 17.6% BN), proximal endoleaks (0.8% GN vs 2.1% BN), and graft migration (0 for both groups) did not reach statistical significance. Neck anatomy precluded EVAR in 106 of 165 (64%) patients with open AAA. CONCLUSIONS: Unsupported endografts with active fixation can yield excellent results in treating many medically compromised patients with hostile neck anatomy. Nonetheless, an unsuitable neck remains the most frequent cause for open abdominal AAA.     

Should patients with challenging anatomy be offered endovascular aneurysm repair?

OBJECTIVES: Treatment of abdominal aortic aneurysm is controversial in patients at high physiologic risk for open repair and high anatomic risk for endovascular repair. We compared outcome in patients at high risk because of anatomy (short or angulated neck), severe occlusive disease, or bilateral iliac aneurysms (group A) with outcome in patients at low risk (group B). MATERIAL AND METHODS: Patients at high anatomic risk who underwent treatment between October 1998 and March 2002 with the Zenith endovascular graft (group A) were compared with patients at low anatomic risk enrolled in a prospective multicenter trial (group B). Variables compared included overall mortality, need for secondary interventions, development of endoleak, and change in aneurysm sac diameter. The chi(2) test, Student t test, and proportions analysis were used to assess the data. RESULTS: Data for 493 patients (group A, 141; group B, 352) were evaluated. Mean follow-up was 9 months (range, 1-24 months). Perioperative mortality was similar for groups A and B (0.7% vs 1%). Frequency of endoleak was higher in patients with high-risk anatomy (25% vs 11%), but not significantly so (P >.06). The rate of aneurysm shrinkage, even in the absence of endoleak, was slower in group A (P <.05). CONCLUSIONS: In physiologically challenged patients at higher anatomic risk for endovascular aneurysm repair, initial mortality rate is similar to that in patients at lower risk. Short-term technical results are acceptable. Decreased long-term survival (largely unrelated to the procedure), slightly higher frequency of endoleak, and a lower rate of sac shrinkage may temper enthusiasm for endovascular repair in this subgroup. Risks of repairing aneurysms in this patient population must be viewed in the context of expected results of intervention or medical observation.     

Is neck dilatation after endovascular aneurysm repair graft dependent? Results of 4 US Phase II trials

Long-term success of endovascular aneurysm repair (EVAR) relies on a stable proximal neck. The authors' goal was to determine whether neck dilatation after EVAR varies among 4 different endografts and whether it is related to complications of the proximal neck. Core laboratory data from 4 phase II trials of aortic endografts were analyzed for neck diameter changes over time. Patients who had at least 24 months' follow-up were included in the analysis. Neck measurement methodology varied among the 3 core labs used. Values are reported within the parameters used by each lab. Short-axis neck diameter close to 5 mm below the renal arteries, when available, was used for longitudinal comparisons. Dilation was defined as an enlargement of 3 mm or more from the first postoperative scan to the last available follow-up for each patient. Graft migration and late proximal endoleaks were determined by the individual core labs. A limited number of Lifepath grafts had most recent follow-up measurements performed by the authors. Results were compared by using Student's t test, chi-square analysis, and the Pearson correlation coefficient. Postoperative measurements from 729 EVAR patients were examined. Follow-up ranged from 24 to 60 months for 229 Ancure (Guidant) and 258 AneuRx (Medtronic) patients, and from 24 to 36 months for 211 Excluder (Gore) and 31 first-generation Lifepath (Edwards) patients. Neck dilation was noted in 124 patients (17.0%) and did not differ significantly among graft types. The incidences of late proximal endoleaks were similar among graft types, but rates of migration differed (p=0.01). Dilation was associated with migration in Ancure (p=0.03) and Excluder (p=0.02) grafts. Late proximal endoleaks were seen in 4.1% of patients with and in 0.7% of patients without dilation (p=0.001). Patients with initial neck diameter >25 mm had significantly less dilatation than those with smaller necks (p<0.001). The incidence of neck dilation approached 20% in all EVAR patients after 24 months and was not significantly different among graft types. Neck dilation of 3 mm or more appears to be one risk factor for migration and late proximal endoleak.     

Early aneurysm recurrence after technically satisfactory Guglielmi detachable coil therapy: is early surveillance needed? Case report

Guglielmi detachable coil (GDC) therapy was initially intended as a treatment for select patients harboring aneurysms deemed to be at high risk for clip ligation. As experience with the technique has grown, many centers are now offering GDC therapy as a primary treatment to patients who are also good surgical candidates. The authors report a case in which a ruptured anterior communicating artery aneurysm recurred within 2 weeks of a technically satisfactory GDC procedure. The patient subsequently underwent successful surgery for clip ligation of the lesion. This is the earliest reported recurrence of an aneurysm after angiographically confirmed successful GDC therapy and underscores the need for performing early control angiography in patients undergoing this procedure.     

Is three-dimensional computed tomography reconstruction justified before endovascular aortic aneurysm repair?

OBJECTIVES: The endovascular management of abdominal aortic aneurysm (AAA) relies on accurate preoperative imaging for proper patient selection and operative planning. Three-dimensional (3-D) computed tomography (CT) with reformatted images perpendicular to blood flow has gained popularity as a method of AAA assessment and image-based planning before endovascular aneurysm repair (EVAR). The current study was undertaken to determine the interobserver agreement of AAA measurements obtained with axial CT and reformatted 3-D CT and to compare the consistency of the 2 methods in selecting patients for EVAR. METHODS: Eight observers assessed the axial CT and reformatted 3-D CT scans for 5 patients with AAAs to determine whether the patients were candidates for EVAR. 3-D CT with multiplanar reformatted images was performed by Medical Media Systems (MMS). Each observer measured the length and diameter of the proximal neck, maximal AAA, aortic bifurcation, common iliac diameter, and aortic angulation. The proximal neck and common iliac arteries were also assessed for thrombus, calcification, and tortuosity. Agreement of the measurements on axial CT scans was compared with those on MMS CT scans by calculating the kappa statistic. Complete agreement was defined as kappa = 1.0. The limits of agreement between observers were also calculated. RESULTS: The cumulative interobserver agreement of MMS CT scans (kappa =.81) was greater than for axial CT scans (kappa =.59). The kappa value for each of the diameter measurements was greater with the MMS CT scans. In 79% of cases the observers' measurements were less than 2 mm from the mean with MMS CT, compared with 59% for axial CT. The kappa value for deciding whether a patient was an endograft candidate on the basis of aortic neck was greater with the MMS CT (0.92 vs 0.63). The limits of agreement between observers were also better with the MMS CT. CONCLUSIONS: The interobserver agreement in planning EVAR is significantly better with MMS CT compared with traditional axial CT. The routine use of MMS CT appears justified before EVAR to improve the accuracy and consistency of patient selection.     

Is cross-femoral bypass grafting a disadvantage of aortomonoiliac endovascular aortic aneurysm repair?

PURPOSE: The need for cross-femoral bypass grafting (CFBG) is considered by some to be a major disadvantage of endovascular aneurysm repair (EVAR) with the aortomonoiliac technique. To determine the durability of CFBG in this setting, we examined data from 148 consecutive high-risk patients in a clinical trial of EVAR with a custom-made aortomonoiliac endovascular stent graft. METHODS: All data were collected prospectively. After hospital discharge, patients were evaluated at 1, 3, and 6 months and annually thereafter. All CFBG was constructed of expandable polytetrafluoroethylene. RESULTS: During follow-up averaging 23.6 +/- 16.2 months, nine CFBG complications developed in 8 patients (5.4%), including disruption (n = 2), infection (n = 3), thrombosis (n = 2), and pseudoaneurysm (n = 3). Four patients with CFBG complications died, of consequences of infection (n = 2), intracranial hemorrhage during attempted CFBG thrombolysis (n = 1), and intracranial hemorrhage during anticoagulation (n = 1). There were no amputations. At life table analysis, freedom from CFBG complication was 96.3% +/- 1.6% at 12 months, 94.1% +/- 2.2% at 24, 36, and 48 months, and 86.2% +/- 7.8% at 60 months. Overall survival for this high-risk patient group was 83.4% +/- 3.1% at 12 months, 70.4% +/- 4.1% at 24 months, 56.5% +/- 5.3% at 36 months, and 44.8% +/- 6.4% at 48 months. CONCLUSION: CFBG is durable, with a low rate of complications in patients undergoing aortomonoiliac EVAR. Need for CFBG should not discourage use of aortomonoiliac devices in patients with anatomy unfavorable for other EVAR approaches.     

Is there a selection bias in applying endovascular aneurysm repair for rupture?

Accumulating data suggest that endovascular repair (EVAR) of ruptured abdominal aortic aneurysms (RAAAs) leads to reduced mortality, but concern exists that this may reflect selection bias. We reviewed our overall rupture experience early after our protocol was instituted to explore this question. We instituted a defined protocol for RAAA with emphasis on EVAR in July 2002, which included device availability (consignment), preoperative training, 24-hr access to our surgical endosuite and ability to operate imaging in an emergency, and immediate availability of a transbrachial balloon cutdown cart for all cases. Charts of all RAAA patients who arrived in the operating room alive since institution of our protocol were reviewed. Computed tomographic (CT) scans were re-reviewed to assess potentially suitable anatomic candidates. From July 2002 to May 2006, a total of 52 RAAAs were treated at our institution: 15 pararenal RAAAs, all treated by open repair (PR-OPEN), and 37 infrarenal RAAAs, 20 treated by open repair (IR-OPEN) and 17 treated by EVAR (IR-EVAR, 32% of all ruptures). Mortality rates in the three groups were 47%, 75%, and 35% (p < 0.02 vs. IR-OPEN), respectively. Although mortality was significantly lower in the EVAR group, overall mortality was 53% (28/52). On re-review of the operative notes and CT scans, it is estimated that more than half of those cases repaired using open techniques could have been repaired using EVAR based on anatomic criteria alone. The most common reason for open repair was hemodynamic instability preoperatively; only a minority of cases were excluded from EVAR based on unfavorable anatomy after CT scan review in the emergency room. In conclusion, during our early experience EVAR for rupture was associated with significantly reduced mortality. However, our overall mortality was no different from historical values, and this fact along with the extremely high mortality seen in the IR-OPEN group suggest that we are simply selecting patients with the greatest chance of survival to undergo EVAR. It also appears that many patients who are anatomically suitable for EVAR are undergoing open operation because of hemodynamic instability. If EVAR for rupture truly decreases mortality in all patients, a much more aggressive attitude toward EVAR may be required to lower the overall mortality rate.     

Diameter of abdominal aortic aneurysm and outcome of endovascular aneurysm repair: does size matter? A report from EUROSTAR

OBJECTIVES: This study was undertaken to determine the effect of the preoperative diameter of abdominal aortic aneurysms on the midterm outcome after endovascular abdominal aneurysm repair (EVAR). METHOD: The data for 4392 patients who had undergone EVAR were analyzed. Patients were enrolled over 6 years to June 2002 in the EUROSTAR database. Outcomes were compared between three groups defined by the preoperative diameter of the aneurysm: group A (n = 1962), 4.0 to 5.4 cm; group B (n = 1528), 5.5 to 6.4 cm; and group C (n = 902), 6.5 cm or larger. Patient characteristics, details of aortoiliac anatomy, operative procedures, old or current device generation, and postoperative complications in the three patient groups were compared. Outcome events included aneurysm-related death, unrelated death, conversion, and post-EVAR rupture of the aneurysm. Life table analysis and log-rank tests were used to compare outcome in the three study groups. Multivariate Cox models were used to determine whether baseline and follow-up variables were independently associated with adverse outcome events. RESULTS: Patients in group C were significantly older than patients in groups A and B (73 years vs 70 and 72 years, respectively; P =.003 - P <.0001 for different group comparisons), and more frequently were at higher operative risk (American Society of Anesthesiologists classification >or=3; 63% vs 48% and 54%; P =.0002-P <.0001). Device-related (type I) endoleaks were more frequently observed at early postoperative arteriography in group C compared with groups A and B (9.9% vs 3.7% and 6.8%; P =.01-P <.0001). Postoperatively systemic complications were more frequently present in group C (17.4% vs 12.0% in group A and 12.6% in group B; P <.0001 and.001). The first-month mortality was approximately twice as high in group C compared with the other groups combined (4.1% vs 2.1%; P <.0001). Late rupture was most frequent in group C. Follow-up results at midterm were less favorable in groups C and B compared with group A (freedom from rupture, 90%, 98%, and 98% at 4 years in groups C, B, and A, respectively; P <.0001 for group C vs groups A and B). Aneurysm-related death was highest in group C (88% freedom at 4 years, compared with 95% in group B and 97% in A; P =.001 and P <.0001, respectively; group B vs A, P =.004). The annual rate of aneurysm-related death in group C was 1% in the first 3 years, but accelerated to 8.0% in the fourth year. Incidence of unrelated death also was higher in groups C and B than in group A (76% and 82% freedom at 4 years vs 87%; P <.0001 for both comparisons). Ratio of aneurysm-related to unrelated death was 23%, 21%, and 50% in groups A, B, and C, respectively. Cox models demonstrated that the correlation between large aneurysms (group C) and all assessed outcome events was independent and highly significant. Older generation devices had an independent association with aneurysm-related and unrelated deaths (P =.02 and P =.04, respectively). However, this correlation was less strong than large aneurysm diameter (P =.0001 and P =.0009, respectively). CONCLUSIONS: The midterm outcome of large aneurysms after EVAR was associated with increased rates of aneurysm-related death, unrelated death, and rupture. Reports of EVAR should stratify their outcomes according to the diameter of the aneurysm. Large aneurysms need a more rigorous post-EVAR surveillance schedule than do smaller aneurysms. In small aneurysms EVAR was associated with excellent outcome. This finding may justify reappraisal of currently accepted management strategies.     

Aneurysm morphology as a predictor of endoleak following endovascular aortic aneurysm repair: do smaller aneurysm have better outcomes?

Since the Food and Drug Administrations' approval of endovascular devices for abdominal aortic aneurysm (AAA) repair, clinicians have been relaxing the strict inclusion criteria present during the clinical trials. Although the long-term natural history of endoleaks remains unclear, attachment site leaks (type I) are believed to represent an ongoing risk for future rupture. We reviewed our experience with endovascular AAA repair to elucidate factors that predispose toward the development of endoleaks and found that larger AAAs are significantly more likely to have a short proximal neck and severe proximal angulation. These factors likely contribute to the significantly increased rate of type I endoleaks that occurred after endovascular repair of large AAAs. Small AAAs (<5) had the lowest rate of endoleaks overall (8.3%) and of type I endoleaks in particular (0%). We conclude that AAA size and morphology can be used to predict which aneurysms will experience attachment site endoleaks in their course; AAAs from 4.5 to 5 cm in diameter may be particularly well suited for endovascular repair in this regard.     

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.     

Mid-term results of endovascular abdominal aortic aneurysm repair: Is it possible to predict sac shrinkage?

Purpose  

To evaluate the mid-term results of endovascular repair of abdominal aortic aneurysms and to predict subsequent sac shrinkage.