Analysis of renal function after aneurysm repair with a device using suprarenal fixation (Zenith AAA Endovascular Graft) in contrast to open surgical repair

PURPOSE: This study was undertaken to assess the effect on renal function of open surgery and endovascular abdominal aortic aneurysm (AAA) repair with suprarenal fixation with the Zenith device. METHODS: Data for 279 patients with similar preoperative comorbid conditions were prospectively analyzed after AAA repair. One hundred ninety-nine patients underwent endografting with the Zenith AAA Endovascular Graft, which incorporates suprarenal fixation (Zenith standard risk group, ZSR), and 80 patients underwent open surgery (standard surgical risk group, SSR). Endovascular repair was also performed in 100 patients considered poor candidates for open repair (Zenith high risk group, ZHR). Serum creatinine concentration (SCr) and anatomic defects were assessed before the procedure, before discharge, and at 1, 6, 12, and 24 months in all patients who underwent endovascular repair, and before the procedure and at 1 and 12 months in patients who underwent open surgical repair (only SCr was measured before discharge). Renal function was also analyzed, with a creatinine clearance calculation (Cockcraft-Gault). Renal insufficiency was defined as an increase in SCr greater than 30% from a preoperative baseline value, any SCr concentration in excess of 2.0 mg/dL, or any need for dialysis. Cumulative renal infarction and arterial occlusion rates were calculated with computed tomographic, ultrasonographic, and angiographic data, and reported as cumulative values. RESULTS: Despite the initially superior renal function in the ZSR group at the pre-discharge evaluation (P =.01), there were no differences at 12 months with respect to rise in SCr greater than 30% (ZSR, 16%, vs SSR, 12%; P =.67), SCr rise greater than 2.0 mg/dL (ZSR, 2.5%, vs SSR, 3.4%; P =.66), incidence of renal artery occlusion (ZSR, 1%, vs SSR, 1.4%; P >.99), or infarction (ZSR, 1.5%, vs SSR, 1.4%; P >.99). Only one patient in each group required hemodialysis. Of note, both groups of patients demonstrated a reduction in creatinine clearance over 12 months, which then stabilized or improved by 24 months for ZSR patients. CONCLUSIONS: Renal dysfunction occurs in a subset of patients regardless of type of repair (open or endovascular with suprarenal fixation). The cause of renal dysfunction after open or endovascular repair with a suprarenal stent is probably multifactorial. The observed dysfunction occurs in a small number of patients, and the effect in the endovascular group (no data for the surgical group at 24 months) appears to be transient. The initial dysfunction, apparent in both groups over 12 months of follow-up, stabilizes or improves at 12 to 24 months.     

The Zenith AAA endovascular graft for abdominal aortic aneurysms: clinical update

PURPOSE: The aim of this study was to provide an update regarding the US clinical trial assessing the performance of the Zenith AAA Endovascular Graft in the treatment of abdominal aortic aneurysms. MATERIALS AND METHODS: A prospective, nonrandomized, concurrent control-based study design was used to contrast conventional repair of infrarenal aneurysms with endovascular repair in patients that would otherwise be candidates for open surgical procedures. Additional study arms allow high-physiologic-risk patients and roll-in patients to be treated using the same endovascular device in a registry format. Patients were evaluated clinically and radiographically computed tomography (CT) and abdominal radiographs) before any intervention, at hospital discharge, 30 days, 6 months, 12 months, and yearly thereafter. Data were analyzed with the intent of assessing acute and chronic morbidity and mortality, radiographic parameters indicative of successful aneurysm repair, and device integrity. RESULTS: A total of 352 patients were treated with the Zenith graft (one patient did not receive an implant in the standard-risk group), and 80 patients underwent conventional surgical repair. Two hundred patients were enrolled in the standard-risk group, 100 in the high-risk group, and 52 underwent endovascular repair as roll-in patients. All cause mortality, aneurysm-related deaths, and ruptures were statistically identical between the groups. Procedural morbidity was significantly lower for patients treated with endovascular grafts with respect to cardiac, pulmonary, renal, and vascular complications. Secondary interventions were more commonly required in the endovascular group. The endoleak rate was 4.9% at 12 months in the standard-risk endovascular group. There was one rupture in the high-risk subset of patients and 3 elective conversions. A total of 1.6% of the endovascular patients were noted to have a barb separation without evidence of significant migration or clinical events. No other device integrity issues were observed. CONCLUSIONS: The safety of the Zenith endovascular graft was superior to conventional management with respect to morbidity and clinical utility. The short-term device efficacy was satisfactory; however, longer-term follow-up will be necessary to establish the duration of this observation.     

Durability of benefits of endovascular versus conventional abdominal aortic aneurysm repair

PURPOSE: Endovascular abdominal aortic aneurysm (AAA) repair is reported to result in less initial patient morbidity and a shorter hospital length of stay (LOS) when compared with conventional AAA repair. We sought to examine the durability of this result during the intermediate follow-up interval. METHODS: The records of all admissions for all patients who underwent AAA repair during a 26-month interval were reviewed. RESULTS: Three hundred thirty-seven (337) patients underwent procedures to repair AAAs (163 open and 174 endovascular). Endovascular procedures were performed with a variety of devices (Talent, 108; Ancure, 36; AneuRx, 26; Zenith, 2; and Cordis, 2) and configurations (141 bifurcated and 33 aortomonoiliac). The mean follow-up period was 10.6 months (endovascular repair) and 12.3 months (open repair). LOS did not significantly vary by device (P =.24 to P =.92) or configuration (P =.24). The initial median LOS for procedures was significantly shorter (P =.009) for endovascular repairs (5 days) than for open procedures (8 days). However, the patients who underwent endovascular repair were more likely to be readmitted during the follow-up interval when compared with patients who underwent open procedure. The readmission-free survival rate after AAA repair at 12 months was 95% for patients for open AAA repair versus 71% for patients for endovascular repair (P <.001). If the total hospital days were compared, including the initial and all subsequent AAA-related admissions, there was no significant difference for mean LOS for patients who underwent endovascular versus open AAA procedures (11 days versus 13.6 days; P =.21). The patients for endovascular AAA repair most commonly needed readmission for treatment of endoleak (n = 31), wound infection (n = 12), and graft limb thrombosis (n = 9). Although women had similar LOS to men for endovascular repair (P =.44), they had longer initial LOS for open AAA repair (15 versus 10 days; P =.03). After endovascular repair, women were more likely than men to be readmitted by 12 months (51% versus 71% readmission-free survival rate; P =.03) and they had longer LOS on readmission (13.2 versus 5.2 days; P =.006). No gender differences were identified for patients after open AAA repair regarding readmission-free survival rate (P =.09) or LOS on readmission (P =.98). CONCLUSION: Although initial LOS was shorter for the patients who underwent endovascular as compared with conventional AAA repair, this advantage was lost during the follow-up interval because of frequent readmission for the treatment of procedure-related complications, chiefly endoleak. These readmissions frequently involved the performance of additional invasive procedures. Gender differences existed regarding LOS and the likelihood of complications after open and endovascular AAA repair.     

An analysis of standard open and endovascular surgical repair of abdominal aortic aneurysms in octogenarians

While elective open abdominal aortic aneurysm (AAA) repair has been shown to be safe in selected octogenarians, very little is known about the role of endovascular AAA exclusion in this high-risk cohort. A retrospective review of our vascular surgical registry from January 1996 to December 2001 revealed 51 octogenarians that underwent infrarenal AAA repair. Since 1999 all octogenarians who presented for AAA repair were evaluated for preferential endovascular stent graft placement. Over the 6-year period, 35 patients underwent standard open repair while 16 patients were found to be anatomic candidates for and were treated with an endovascular stent graft. Hospital and office charts were reviewed to compare the endovascular cohort to the standard open cohort. Factors considered included patient comorbidities, perioperative data, and operative outcomes. Statistical analysis was done using Wilcoxon rank sum test and Fisher exact test. The median age for the entire group was 83 years. There were 11 females in the open group and 1 female in the endovascular group. There were no statistically significant differences in preoperative patient comorbidities between groups. Total mortality for the entire series was 11.8 per cent but this included 5 ruptured AAAs, all of which patients died, and 11 additional AAAs that were symptomatic, of which 1 patient died. Total nonruptured mortality for the entire series was 2.2 per cent (0% for the endo-group and 3.3% for the open group). There were statistically significant differences between the endovascular versus the open groups when comparing aneurysm diameter (5.6 cm vs. 6.2 cm; P = 0.016), estimated blood loss (225 cc vs. 2100 cc; P < 0.001), ICU days (0 vs. 3; P < 0.001), length of hospital stay (2 days vs. 12 days; P < 0.001), and patients with blood transfusions (1 vs. 27; P < 0.001). When comparing postoperative morbidities, 4 of the endovascular patients (25%) and 25 of the open patients (68.6%) had a complication (P = 0.006). In conclusion, endovascular stent graft treatment of nonruptured infrarenal AAAs in octogenarians led to significantly better outcomes and should probably be considered the preferred treatment whenever anatomically appropriate. Endovascular exclusion of ruptured AAAs may potentially improve future outcomes in this high-risk group.     

Rupture of abdominal aortic aneurysm: concurrent comparison of outcome of those occurring after endovascular repair versus those occurring without previous treatment in an 11-year single-center experience

OBJECTIVE: The purpose of this single-center study was to compare findings at presentation and surgical outcome in patients in whom abdominal aortic aneurysms (AAAs) ruptured after endovascular repair and patients in whom AAAs ruptured before any treatment, over a defined period. METHODS: From May 1992 to September 2003, 1043 patients underwent elective repair of intact infrarenal AAAs. Endovascular repair was performed in 609 patients, and open repair in 434 patients. Eighteen of 609 patients (3%) who underwent endovascular AAA repair required treatment because of rupture of the aneurysm after a mean of 29 months (group 1). During the same 11-year period, another 91 patients without previous treatment required urgent repair of a ruptured AAA (group 2). Rupture was diagnosed at contrast material-enhanced computed tomography or by presence of extramural extravasation of blood at open repair. Except for a higher incidence of women in group 2, patients in both groups were similar with regard to demographics and clinical characteristics but differed in findings at presentation. Eight patients in group 1 had a known endoleak before AAA rupture, whereas contrast-enhanced computed tomography, performed in 15 patients at presentation, demonstrated an endoleak in all. Hypotension (systolic blood pressure <100 mm Hg) was noted at presentation in 4 of 18 patients (22%) in group 1 and 76 of 91 patients (84%) in group 2. All patients underwent open repair via a transperitoneal approach, except for 4 patients in group 1 and 3 patients in group 2 who underwent endovascular repair of ruptured AAAs. RESULTS: The proportion of patients with hypotension at presentation in group 1 (4 of 18) was significantly less than in group 2 (76 of 91; P < .01). The difference in perioperative (30 day) mortality rate in group 1 (3 of 18; 16.6%) compared with group 2 (49 of 91; 53.8%) was also significant (P < .01). The outcome in group 1 was therefore superior to that in group 2. CONCLUSIONS: This study confirms that endovascular AAA repair complicated by endoleak does not prevent rupture. The data suggest, however, that rupture, when it occurs in these circumstances, may not be accompanied by such major hemodynamic changes and high mortality as rupture of an untreated AAA. Further long-term follow-up and analysis in a larger group of patients are required to confirm the apparent intermediate level of protection afforded by failed endovascular repair, which does not prevent rupture but enhances survival after operation to treat rupture, possibly by ameliorating the hemodynamic changes associated with the rupture process.     

Laparoscopy-assisted aneurysm resection as a minimal invasive alternative in patients unsuitable for endovascular surgery

OBJECTIVE: So far, endovascular surgery has been the only minimal invasive way to treat patients with abdominal aortic aneurysms (AAAs). With hand-assisted laparoscopic surgery (HALS), laparoscopic transperitoneal endoaneurysm repair can be performed through a 6-cm mini-incision only. We wanted to evaluate whether this laparoscopic technique can be offered as a minimal invasive alternative in patients unsuitable for endovascular AAA repair. MATERIAL AND METHODS: Forty patients were referred for endovascular AAA repair. Three patients had to be excluded from the study. Endovascular AAA exclusion was finally performed in 13 patients. Laparoscopic AAA resection was performed in 24 patients. Hand-assisted laparoscopic surgery with transperitoneal access and endoaneurysm repair was accomplished in all patients unsuitable for an endovascular procedure. The outcome after endovascular repair was compared with the outcome of patients who underwent laparoscopy. RESULTS: In the laparoscopic group, conversion to an open procedure was necessary in one case. One patient in this group died (4.1%) postoperatively. There were four complications in each group. In the endovascular group we had one endoleak type II and one graft thrombosis, which required a reoperation. After endovascular treatment, patients were transferred significantly less frequently to the intensive care unit, and they could resume oral feeding earlier. Mobilization and postoperative hospital stay did not differ significantly between the groups. CONCLUSION: Laparoscopic AAA resection with the use of the technique described can be routinely offered to patients unsuitable for endovascular AAA exclusion with excellent long-term results similar to open surgery. A controlled study is clearly indicated to evaluate the role of laparoscopic techniques in aneurysm surgery.     

Aortic necks of ruptured abdominal aneurysms dilate more than asymptomatic aneurysms after endovascular repair

BACKGROUND: Endovascular repair of abdominal aortic aneurysm (AAA) is increasingly used. We evaluated if a difference exists in the rate of change of the aortic neck diameter between non-ruptured and ruptured AAAs after endovascular aneurysm repair (EVAR). METHODS: Details of patients undergoing elective (group I) and emergency (group II) EVAR using Talent stents between October 1999 and September 2005 were reviewed. Top neck diameters were prospectively recorded on the hospital database from computed tomography scans preoperatively and at 1, 3, 12, and 24 months postoperatively. The aortic neck diameter rate of change was calculated for each group. RESULTS: Endovascular repair was performed on 110 elective and 41 emergency patients, of which 100 (80 male) elective and 29 (26 male) emergency patients were included in this analysis. Mean age was similar in each group. Stents were oversized by 20.9% +/- 13.6% in group I and by 24.7% +/- 16.3% in group II (P = .37). The preoperative mean proximal aortic neck was larger in group II (25.0 +/- 3.3 mm vs 23.5 +/- 2.8 mm; P = .029). The growth rate of the top neck diameter was significantly greater at 12 months (1.48 +/- 2.4 mm/year vs 3.89 +/- 6.24 mm/year; P = .04) and 24 months (.99 +/- 1.1 mm/year vs 2.61 +/- 3.3 mm/year; P = .04) in group II than in group I. A decreasing sac size was found in 68.2% of patients whose neck dilated. The complication rate was similar in each group. CONCLUSION: Aneurysm necks in patients with ruptured aneurysms are larger and dilate at a greater rate than those with nonruptured aneurysms. The accelerated rate of expansion in some patients must be borne in mind during follow-up and in secondary endovascular interventions and conversion to open surgery.     

Acute and chronic open conversion after endovascular aortic aneurysm repair: a 14-year review

OBJECTIVE: This study reviewed outcomes of patients requiring surgical conversion after endovascular abdominal aortic aneurysm (AAA) repair. METHODS: Records for all patients undergoing open conversion after endovascular AAA repair were reviewed. RESULTS: From 1993 to 2006, 574 patients underwent endovascular repair for AAA. Seventeen patients, including three patients who underwent prior endovascular repair at other centers, required surgical conversion with complete (n = 9) or partial graft removal (n = 8). Five patients required immediate conversion (acute), and 12 underwent delayed conversion 4 to 72 months after endovascular repair. Indications for acute conversion were large type I endoleak (n = 3, 60%), including one patient with graft migration, and retroperitoneal bleeding (n = 2, 40%). Indications for chronic conversion were endoleak with increasing aneurysm size (n = 9, 75%), stent fracture without endoleak (n = 1, 8%), delayed retroperitoneal bleeding (n = 1, 8%), and infection (n = 1, 8%). Suprarenal aortic cross-clamping was required in two patients (12%), and endograft components were retained in eight (47%). An aortic occlusion balloon placed through the body of the existing endograft facilitated proximal control in three patients. There were two perioperative deaths in the acute conversion group (2/5; 40%) and none in the delayed conversion group (P = .04). Five-year actuarial survival was 71.9%. Mean follow-up was 41.6 +/- 32.2 months. Retained endovascular components in patients with partial graft removal remained stable during follow-up. CONCLUSIONS: Surgical conversion after endovascular AAA repair can be performed without suprarenal clamping in most patients. Endovascular aortic control with a balloon avoids suprarenal exposure. Partial endograft removal in selected patients facilitates open conversion and appears durable. Acute conversion is associated with increased mortality.     

Endovascular stent-graft repair for abdominal aortic aneurysm in a patient with cardiac and renal dysfunction

This case report details our experience with endovascular stent-graft repair for an abdominal aortic aneurysm (AAA) in a patient who was previously treated by left ventricular remodeling for dilated cardiomyopathy. Renal dysfunction with an elevated creatinine level (1.59 mg/dl) was managed by reducing the dose of contrast medium utilizing intravascular ultrasonography. Using a Zenith AAA endovascular device, the aneurysmal sac was successfully excluded and was thrombosed. Endovascular stenting is a good treatment option for abdominal aneurysm repair in patients with poor heart function and renal impairment.     

Initial experience with endovascular aneurysm repair: Comparison of early results with outcome of conventional open repair

Purpose: To determine the safety, effectiveness, and problems encountered with endovascular repair of abdominal aortic aneurysm (AAA). Initial experience with endoluminal stent grafts was examined and compared with outcome for a matched concurrent control group undergoing conventional operative repair of AAA. Methods: Over a 3-year period, 30 patients underwent attempts at endovascular repair of infrarenal AAA. Of the 28 (93%) successfully implanted endografts, 8 were tube endografts, 8 bifurcated grafts, and 12 aortouniiliac grafts combined with femorofemoral bypass. Most of the procedures were performed in the past year because the availability of bifurcated and aortoiliac endografts markedly expanded the percentage of patients with AAA who might be treated with endoluminal methods. The follow-up period ranged from 1 to 44 months, with a mean value of 11 months. Results: Endovascular procedures demonstrated significant advantages with respect to reduced blood loss (408 versus 1287 ml), use of an intensive care unit (0.1 versus 1.75 days), length of hospitalization (3.9 versus 10.3 days), and quicker recovery (11 versus 47 days). Although the total number of postoperative complications was identical for the two groups, the nature of the complications differed considerably. Local and vascular complications characteristic of endovascular repair could frequently be corrected at the time of the procedure and tended to be less severe than systemic or remote complications, which predominated among the open surgical repair group. On an intent-to-treat basis, 23 (77%) of the 30 AAAs were successfully managed with endoluminal repair. The seven (23%) failures were attributable to two immediate conversions caused by access problems, three persistent endoleaks, one late conversion caused by AAA expansion, and one late rupture. Conclusions: Although less definitive than those for conventional operations, these early results suggest that endovascular AAA repair offers considerable benefits for appropriate patients. The results justify continued application of this method of AAA repair, particularly in the treatment of older persons at high risk. (J Vasc Surg 1998;27:992-1005.)     

Endovascular Treatment of Failed Prior Abdominal Aortic Aneurysm Repair

Failure of endovascular or conventional abdominal aortic aneurysm (AAA) repair may occur as a result of attachment site endoleak (type I) or paraanastomotic aneurysm and pseudoaneurysm formation. This study examined the results of the use of secondary endovascular grafts for the treatment of failed prior infrarenal AAA repair procedures. Forty-seven patients were treated with endovascular grafts. These included 14 patients with type I endoleaks (5 proximal, 8 distal, 1 proximal and distal) and 33 patients with paraanastomotic aneurysms after standard open surgical AAA repair (3 proximal aorta, 5 distal aorta, 21 iliac, 4 proximal and distal). The interval between the primary aortic procedure and the endovascular repair was significantly shorter for failed endovascular procedures (mean, 18.2 months; range, 1-42 months) than for failed conventional procedures (mean, 108.9 months; range, 12-216 months) (p <0.01). The endovascular devices used for correction of the failed AAA repairs were Talent (23), physician-made (19), AneuRx (2), Vanguard (2), and Excluder (1). Transrenal fixation was used for repair of all proximal anastomotic failures. Mean follow-up after reintervention was 12.2 months in patients with failed endovascular grafts and 10.6 months in patients with failed conventional grafts. Patient demographics were as follows: average age, 78 years; 36 male and 11 female; and 4.1 comorbid medical conditions per patient. The endovascular graft was successfully deployed in all 47 cases; 1 patient experienced a persistent proximal attachment site endoleak after endograft deployment. Endovascular grafts may be used to treat previously failed endovascular and conventional AAA repair procedures with good short- and intermediate-term results. Endovascular treatments in these cases may avoid the difficulties of aortic reoperation or AAA repair in the setting of prior endovascular aortic grafting.     

Influence of endograft oversizing on device migration, endoleak, aneurysm shrinkage, and aortic neck dilation: results from the Zenith Multicenter Trial

BACKGROUND: Generous endograft oversizing has been associated with propensity for aortic neck dilation and subsequent device migration in endografts without suprarenal fixation. Effects of variable oversizing of endografts with suprarenal fixation have been poorly studied. METHODS: Three hundred fifty-one patients underwent endovascular AAA repair (EVAR) in a prospective multicenter trial using the Zenith AAA Endovascular Graft, a fully supported bifurcated 3-piece endograft with barb-enhanced suprarenal stent fixation. Blinded core-laboratory measurement of variables was prospectively recorded at predischarge and at 1, 6, 12, and 24 months after the procedure. Potential influence of endograft oversizing on subsequent aortic neck dilation (minor axis), aneurysm shrinkage (major axis), device migration, endoleak, rupture, open conversion, and death were retrospectively studied. Data are given as mean +/- SEM. RESULTS: Risk of endograft migration (>5mm) at 12 months was 2.3% (6/261). However, patients with endograft oversizing of >30% had a 14% (4/29) migration risk compared with those oversized < or =30% (0.9%, 2/232), P <.002. There was zero device migration by the SVS definition (>10 mm or clinical event). Device oversizing >30% was associated with decreased AAA sac shrinkage (48% vs 77%) and with increased sac enlargement (9.5% vs 0.6%) at 24 months when compared with oversizing of < or =30%, respectively (P =.001). Incidence rate of any endoleak at 12 and 24 months was 8.2% (21/256) and 7.1% (12/169), respectively. Oversizing of endografts by >30% was associated with an increased type II endoleak rate (11 vs 4.7%) that failed to reach statistical significance (P =.27). Aortic neck diameters increased significantly by 6 months (P <.001) but then stabilized through 24 months; the absolute changes at 1 (n = 298), 6 (n = 278), 12 (n = 264), and 24 months (n = 171) were 0.66 +/- 0.10 mm (3.0%), 1.32 +/- 0.11 mm (5.6%), 1.38 +/- 0.12 mm (5.9%), and 1.44 +/- 0.16 mm (6.1%), respectively. Linear regression analysis demonstrated no correlation between endograft oversizing and aortic neck dilation at 12 (P =.86) or 24 months (P =.64). CONCLUSIONS: Device migration and endoleaks were very infrequent after treatment with the Zenith AAA Endovascular Graft. However, endograft oversizing of >30% was associated with an approximately 14-fold increase in device migration (>5 mm) at 12 months and with a approximately 16-fold increased risk of AAA expansion at 24 months. Although further follow-up will be essential to assess whether these early associations continue, avoidance of excessive endograft oversizing is recommended.     

Endovascular vs open AAA repair: does size matter?

Since the natural tendency of the aorta is to increase in diameter and tortuosity with age and since abdominal aortic aneurysms (AAAs) increase in diameter and length over time, encroaching on the renal and hypogastric orifices, early repair of AAAs (when > or =4.0 cm) may allow greater applicability of the endovascular option because of more favorable aortoiliac morphology. Patients who present at an older age with larger AAAs should be more likely to be anatomically excluded from endovascular AAA repair. Over a 42-month period, 317 consecutive patients referred with aortoiliac aneurysms (infrarenal AAA > or =4.0 cm) were evaluated by one of the authors (SGL) for endovascular vs open repair based on computed tomography (CT) and angiographic imaging. The 10 anatomic exclusion criteria were those applicable to the Zenith endograft (Cook, Inc), which currently is the most anatomically inclusive of the aortic endografts in commercial use in the United States. Based on their aortoiliac morphology, 212 patients were excluded from endovascular repair and 105 were included as acceptable anatomic candidates. Age, AAA size, and the reason(s) for exclusion were recorded for each patient. By use of Student's t test and logistic and linear regression analyses, the groups were compared by age, AAA size, and age + size. There was no significant difference in patient age or AAA size distribution between the group of patients excluded from endovascular repair based on aortoiliac morphology compared to those who met the inclusion criteria. Patients with small AAAs (4.0-5.4 cm) had similar age distribution as those with large (> or =5.5 cm) AAAs. The majority of patients (87%) were excluded based on proximal aortic neck morphology. The presence of aortoiliac morphology that precludes endovascular repair is independent of patient age or AAA size at presentation. A patient presenting with a small (4.0-5.4 cm) AAA is not more likely to be a candidate for endovascular repair than a patient with a large AAA.     

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.     

Endovascular repair of a common iliac artery aneurysm using the Cook Zenith abdominal aortic aneurysm Endovascular Graft Converter

Isolated common iliac artery aneurysm is a rare condition that is treated aggressively because of its high risk of rupture. Endovascular abdominal aortic aneurysm (AAA) repair has recently been extended to the clinical management of the iliac artery aneurysm. Stent grafts have been used successfully to exclude iliac artery aneurysms. Successful graft deployment and aneurysm exclusion require adequate seal and fixation at the proximal and distal attachment sites. This article presents a high-risk surgical patient whose 6.8-cm-diameter iliac artery aneurysm was repaired with a Zenith AAA Endovascular Graft Converter (Cook, Bloomington, Indiana). This device is normally used to convert an aortobiiliac endograft to an aortouniiliac endograft during AAA repair. The tapered 80-mm-long graft has diameters of 24 mm proximally and 12 mm distally. Completion arteriogram demonstrated exclusion of the iliac artery aneurysm with no evidence of endoleak. No postoperative complications occurred. No endoleak was seen on the follow-up abdominal computed tomography scan.     

Impact of endoluminal treatment on small abdominal aortic aneurysm: aneurysm sac regression and secondary interventions with 5 years of follow-up

Does early repair of small abdominal aortic aneurysms (AAAs) lead to faster aneurysm sac regression or less secondary intervention? Computed tomography scans and reconstructions from M2S of all patients undergoing endovascular AAA repair at our institution from 1996 to 2006 were retrospectively reviewed. A small aneurysm is defined as an aneurysm sac to renal diameter ratio of less than 2. There were 374 patients with endovascular AAA repair that had complete imaging studies. There were 75 patients (20%) with small AAAs; of those, 19 patients (25.3%) had endoleak compared with 108 patients (36.1%) with a large aneurysm ( P = .1). Over a mean follow-up time of 42 months (range, 1-109), 11 small AAAs (14.7%) had secondary interventions compared with 58 (19.4%) of the large AAAs (P = .41). Small AAAs at 5 years had a 2.5% volume sac regression but a 3.0% increase in diameter. Those with a large aneurysm had a slight increase in sac volume and diameter at 1 month (3.3%, 1.4%) and then steadily decreased to -13.4% and -8.8% at 5 years. Patients with Endologix (Endologix Inc., Irvine, Calif) devices have the most regression when compared with patients with AneuRx (Medtronic Inc., Minneapolis, Minn) and Talent (Medtronic Inc., Minneapolis, Minn) devices. Early endovascular intervention in small AAAs does not result in faster aneurysm sac regression or secondary intervention. Aneurysm sac regression is significantly affected by endoleak, aneurysm size, and device used.     

Abdominal aortic aneurysmorrhaphy and cholelithiasis in the era of endovascular surgery

The incidence of acute cholecystitis complicating standard abdominal aortic aneurysm (AAA) repair has been reported between 0.3 and 18 per cent. This has prompted considerable debate regarding the management of cholelithiasis discovered incidentally during open aortic reconstruction. This study seeks to determine the incidence of cholelithiasis and acute cholecystitis after endovascular AAA repair and evaluate options for management. Between February 1996 and October 2001 492 patients underwent endovascular AAA repair. All the procedures were performed in the operating room under fluoroscopic guidance. Epidural (98.9%), local (0.5%), or general (1.7%) anesthesia was used during these cases. The incidence of cholelithiasis and acute cholecystitis was evaluated by CT scan and abdominal ultrasound. Serum measurements of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total and direct bilirubin, and amylase were performed and clinical assessment was conducted at 1, 6, and 12 months postoperatively and annually thereafter. The mean age of these patients was 76.6 years; 84% were male. Comorbid medical conditions were present in all patients (average 3.5 conditions/patient). Follow-up ranged from 2 to 35 months (mean 12.8 months). Endovascular stent graft deployment was successful in 486 of the 492 patients (98.8%). Six patients were converted to standard open repair because of inability to achieve successful endovascular aneurysm repair. The perioperative major morbidity rate was 14.9 per cent. Minor morbidity rate was 8.5 per cent. The perioperative mortality rate was 1.9 per cent. No deaths were related to biliary disease. Cholelithiasis was identified in 64 (13%) patients preoperatively. One of 64 patients with a prior Billroth II reconstruction for peptic ulcer disease developed jaundice 8 days after AAA repair as a result of choledocholithiasis that required surgical repair. One patient without gallstones developed acute acalculous cholecystitis on postoperative day 16 as determined on pathologic analysis of the gallbladder. A third patient who had gallstones identified on preoperative CT scan developed calculous cholecystitis 16 months after endovascular AAA repair. These two patients underwent uncomplicated laparoscopic cholecystectomy and recovered uneventfully. The incidence of postoperative symptomatic cholelithiasis is 1.6 per cent (one of 64). The incidence of postoperative acute cholecystitis was 0.2 per cent (one of 486) and was unrelated to the presence of gallstones. The incidence of delayed symptomatic cholelithiasis was 1.6 per cent (one of 64). Endovascular repair of AAA does not appear to predispose the patient to the development of symptomatic cholelithiasis during the perioperative period. Therefore a preoperative or intraoperative diagnosis of cholelithiasis does not necessitate cholecystectomy in the setting of planned endovascular AAA repair. Patients who develop cholecystitis after endovascular AAA repair may be effectively treated by standard laparoscopic techniques.     

The effect of endograft relining on sac expansion after endovascular aneurysm repair with the original-permeability Gore Excluder abdominal aortic aneurysm endoprosthesis

OBJECTIVE: Endovascular abdominal aortic aneurysm repair (EVAR) with the original-permeability Excluder (W.L. Gore & Associates, Flagstaff, Ariz) has been associated with postoperative sac expansion in the absence of endoleak. In these cases, we have performed an endovascular revision, relining the original endograft with another Excluder, in an effort to arrest sac expansion by reducing permeability. We have studied these cases to determine the effect of relining on aneurysm expansion. METHODS: Patients who demonstrated sac expansion (>or=5 mm diameter, >or=5% three-dimensional volume) after EVAR with the original Excluder were evaluated. Between 1999 and 2004, the original-permeability endoprosthesis was used in 97 patients who underwent EVAR for asymptomatic abdominal aortic aneurysm (AAA). Sac expansion occurred in 24 patients, of which multiple imaging modalities showed 12 had expansion without demonstrable endoleak. Nine of the 12 have had endovascular relining, and five of these nine have >6 months follow-up to form the primary basis for this report. RESULTS: AAA size was stable or smaller in the first 6 months after the original EVAR for all patients. Once expansion began (typically in the time frame of 6 to 12 months), multimodality imaging showed no aneurysm spontaneously decreased in size without intervention, despite the absence of endoleak (n = 12). Expansion exceeded clinically significant thresholds at 30 months (mean) by diameter criteria and 22 months (mean) by three-dimensional volume criteria for the five patients with >6 months follow-up after relining. Endovascular relining was performed at a mean of 36 months, with a mean hospital stay of 1 day, and no morbidity or mortality. Over the entire duration of expansion (mean, 26 months), aneurysms expanded by 6.0 +/- 1 mm/year diameter and by 12% +/- 2%/year by three-dimensional volume. At a mean of 16 months follow-up after relining with another Excluder, the mean diameter decrease was 2.0 mm/year (P < .03) and the mean volume decrease was 2.6%/year (P < .01). After relining, all AAAs were smaller by diameter or volume, or both, exceeding thresholds defining shrinkage in two of the five with >6 months follow-up after relining. There was no rupture, migration, endoleak, conversion to open repair, or aneurysm-related death in any patient. CONCLUSIONS: It appears from the initial follow-up that AAA expansion owing to permeability issues after EVAR with the original Excluder can be arrested by endovascular relining with a low-permeability Excluder endoprosthesis.     

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

OBJECTIVE: Small patient numbers, mixed data from clinical trials, and longitudinal series representing institutional learning curves have characterized previous studies of early outcomes after endovascular abdominal aortic aneurysm (AAA) repair. We compared the perioperative outcomes of endovascular and open surgical AAA repair in an unselected sample of patients in a single calendar year using a national administrative database. METHODS: The 2001 National Inpatient Sample database was retrospectively reviewed. This database represents 20% of all-payer stratified sample of non-federal US hospitals. Patients older than 49 years were identified by primary diagnostic codes (International Classification of Disease, ninth revision [ICD-9], 441.4, intact, nonruptured AAA) and procedure codes (ICD-9 38.44 for open, 39.71 for endovascular repair). Patient demographic data (age, sex), comorbid conditions (ICD-9 coded), inpatient complications (ICD-9 coded), length of stay, final discharge disposition (home vs institution vs death), and hospital charges were examined with univariate and multivariate analyses. RESULTS: In calendar year 2001, 7172 patients underwent either open (64%) or endovascular (36%) repair of intact, nonruptured AAAs. Despite comparable rates of preoperative comorbid conditions and a greater proportion of octogenarians (23% vs 16%%; P =.0001), morbidity (18% vs 29%; P =.0001) and mortality (1.3% vs 3.8%; P =.0001) were significantly lower for endovascular repair than for open repair. The median length of stay (2 vs 7 days; P =.0001) and the rate of discharge to an institutional facility versus home (6% vs 14%; P =.0001) were also much lower in the endovascular group than in the open repair group. At multivariate analysis, open AAA repair and age older than 80 years were strong independent predictors (P =.0001 for all) for death (open repair: odds ratio [OR], 3.3; 95% confidence interval [CI], 2.3-4.9; age: OR, 14.2; 95% CI, 3.5-58.1), complications (open repair: OR, 1.9; 95% CI, 1.7-2.1; age: OR, 1.9; 95% CI, 1.5-2.5), and not being discharged to home (open repair: OR, 3.4; 95% CI, 2.9-4.1; age: OR, 12.0; 95% CI, 7.0-20.4). Mean hospital charges were significantly greater (difference, $3337; P =.0009) for endovascular repair than for open repair. Extrapolated to the total number of endovascular AAA repairs performed during the single 2001 calendar year, this resulted in a staggering $50.3 million in additional hospital charges. CONCLUSIONS: Endovascular repair of intact AAAs results in a significantly lower number of complications and deaths, shorter hospital stay, and improved likelihood of discharge to home, even in older patients, when compared with open surgical repair. These impressive gains in clinical outcome, however, are achieved at similarly impressive increases in health care costs.     

Clinical effect of abdominal aortic aneurysm endografting: 7-year concurrent comparison with open repair

OBJECTIVE: We compared the effectiveness and clinical outcome of open repair versus endovascular aortic aneurysm repair (EVAR) in achieving prevention of abdominal aortic aneurysm (AAA)-related death and graft-related complications. METHODS: Over 7 years from 1997 to 2003, 1119 consecutive patients underwent elective treatment of infrarenal AAAs, 585 with open repair and 534 with EVAR. Patients were regularly followed up at 1, 6, 12 months, and every 6 months thereafter, in EVAR group, and at 3 and 12 months, and yearly thereafter after open repair. Preoperative, intraoperative, and follow-up data were stored in a prospective database. RESULTS: Median follow-up was similar in the 2 groups: 33 months (interquartile range [IQR], 13-50 months) in the EVAR group vs 35 months (IQR, 15-54 months) in the open repair group. EVAR group patients were older than patients in the open repair group: 73 years vs 72 years (P = .04). There were statistical significant differences between the EVAR group and the open repair group with respect to AAA median diameter (52 mm vs 56 mm), coronary disease rate (46% vs 37%; P = .001), pulmonary disease rate (56% vs 38%; P < .0001), and American Society of Anesthesiologists IV score rate (16% vs 6%; P < .0001). Thirty-day mortality in the EVAR group was 0.9% (5 of 534 patients), compared with 4.1% (24 of 585 patients; P = .001) in the open repair group, and major morbidity was 9.1% (49 of 534 patients) vs 18.6% (109 of 585 patients; P < .0001), respectively. The incidence of secondary procedures in the EVAR group was 15.7%, compared with 3% in the open repair group (P < .0001). There were no deaths related to secondary procedures in either group. Six AAAs (1.1%) ruptured after EVAR, 3 of which were fatal; in the open repair group 1 patient (0.2%) underwent successful repeat operatation to treat iliac pseudoaneurysm rupture 5 years after the original procedure. Kaplan-Meier estimates for freedom from aneurysm-related death at 84 months were 97.5% in the EVAR group and 95.9% in the open repair group (log rank test, P = .008). Kaplan-Meier survival estimates at 84 months were 67.1% in the open repair group and 66.9% in the EVAR group (P = NS). At the same interval the risk for secondary procedures was 49.4% for the EVAR group and 7.1% for the open repair group. Of the 11 variables analyzed with logistic analysis, open surgery (hazard ratio [HR], 11; 95% confidence interval [CI], 2.5-54.2; P = .002), American Society of Anesthesiologists IV score (HR, 7.1; 95% CI, 2.7-18.8; P = .0001), and age (HR, 1.06; 95% CI, 1.04-1.13; P = .04) were positive independent predictors of perioperative mortality. CONCLUSION: Our data suggest that at a maximum follow-up of 7 years, patients who undergo EVAR show lower perioperative and late aneurysm-related mortality compared with a younger and substantially healthier group of patients with aneurysms treated with open repair. The higher need for secondary procedures in the endovascular group did not affect superiority of the overall performance of EVAR in the early and late intervals.